In Google's latest Webmaster Help video, Matt Cutts is asked about a common SEO misconception that he wishes to put to rest. The answer: Google is not doing everything you read about in patents.
Cutts says, "There a sort of persistent misconception that people often have, which is that just because a patent issues...that has somebody's name on it, or someone who works at search quality, or someone who works at Google, that doesn't necessarily mean that we are using that patent at that moment."
He continues, "Sometimes you'll see speculation, 'Oh, Google had a patent where they mentioned using the length of time that the domain was registered.' That doesn't mean that we're necessarily doing that. It just means that, you know, that mechanism is patented."
Cutts recalls, "Somebody else at Google had gotten a patent on the idea (or the mechanism, not just the idea, the actual implementation) by which you could look at how people had changed their webpage after an update, and basically say, 'Oh, these are people who are responding to Google, or they are dynamically SEOing their stuff,' and so there were a lot of publishers who were like, 'Ugh, I'm just gonna throw up my hands. Why bother at all if Google's just gonna keep an eye?' and you know, 'If we change, and Google's just using that and monitoring that, and changing their ranking in response,' and it's the sort of thing where just because that patent comes out, doesn't mean that Google's currently using that technology."
"So, patents are a lot of interesting ideas," he adds. "You can see a lot of stuff mentioned in them, but don't take it as an automatic golden truth that we're doing any particular thing that is mentioned in a patent."
It is true that patents provide a lot of insight into the kinds of ideas that Google is thinking about, and often we can only really speculate about certain things that it is actually implementing.